FIG. 1 illustrates a system 100 for Generic Advertisement Service (GAS) and Access Network Query Protocol (ANQP) operation. The system includes stations (STAs) 102, an access point (AP) 104, a service provider network 106, roaming hubs 108, and home location registers (HLRs) 110. The various components may be arranged as shown in FIG. 1. First, a user 102 chooses to connect to Wi-Fi, and the user's device scans for available hotspots. IEEE 802.11u GAS is used to provide for Layer 2 transport of an advertisement protocol's frames between a terminal and a server in the network prior to authentication. Institute of Electrical and Electronics Engineers (IEEE) 802.11u ANQP is used to discover different features and available services of the network. The device then proceeds with the authentication process.
A STA 102 may be any of the devices illustrated in FIG. 1, such as a cell phone, laptop, tablet, smart sensor, handheld or consumer electronic device, and other user devices that have a WiFi interface that can interact with a WiFi network. These devices also may be able to interact with other types of communication networks, such as a cellular network. An AP 104 and one or more STAs 102 can form a basic service set (BSS), which is the basic building block of an IEEE 802.11 wireless local area network (WLAN). An AP 104 may communicate with an AP controller or an ANQP server, which can be collocated or not with the AP 104. A BSS generally can be identified by a service set identifier (SSID), which is configured and may be broadcasted by the AP 104.
It is expected that WiFi systems will support a large number of stations (STAs) with improved network capacity, thanks to advances in communication technologies. In other words, access points (APs) should be capable to handle a large number of communication requests simultaneously when mobile devices enter and leave the WiFi domains. For example, in a train station when the train stops, many WiFi users that are video streaming or browsing the Internet may come out the train at the same time and try to associate with the AP in the station and continue their video or Internet browsing. In the power outage area, smart meters need to transmit a “last gasp” notification message that alerts the distributor to their loss of power. Moreover, after a long power outage, multiple devices such as smart meters may try to re-associate with the AP. In such cases, a large number of STAs with different types of messages may communicate with the AP in a burst manner. However, due to the contention nature of carrier sense multiple access with collision avoidance (CSMA/CA), simultaneous communications will cause collisions and thus result in a long channel access delay. An overly long access delay may not only cause more energy consumption of mobile devices, but also jeopardize the quality of service (QoS) provisioning of multimedia services. Hence, QoS-aware network association in a WiFi system in support of multiple types of STAs should be considered.